Rapid transmission of the protozoan parasite<i>Histomonas meleagridis</i>in turkeys and specific pathogen free chickens following cloacal infection with a mono-eukaryotic culture

Heß, Michael; Grabensteiner, Elvira; Liebhart, Dieter

doi:10.1080/03079450600815507

Cited by 61 publications

(51 citation statements)

References 25 publications

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“…This is in agreement with other studies where this disease was induced by horizontal transmission (Hu & McDougald, 2003;Hess et al, 2006;Liebhart & Hess, 2009) although small differences in first day of death and mortality were noted probably due to differences in histomonas strain (McDougald, 2005a). Horizontal transmission likely occurs via the cloacal route (Hu et al, 2004) as retrograde transport of cloacal fluids to the caecum is fast (Akester et al, 1967), while oral inoculation with lumen stages of the parasite, probably due to the acidity of the gizzard, often fails to result in disease (Farmer & Stephenson, 1949;Horton-Smith & Long, 1956;Lund, 1956).…”

Section: Discussionsupporting

confidence: 94%

“…The first H. meleagridis shedding poults were found 1 day p.i., which is 1 day earlier than reported by others (Hess et al, 2006). This may have been caused by the lower detection limit of our qPCR.…”

Section: Discussioncontrasting

confidence: 40%

“…H. meleagridis-infected turkeys may develop typhlitis and hepatitis as main lesions, which are often fatal. Mortality frequently soars up to 80-100%, both under field and experimental conditions (Hu & McDougald, 2003;McDougald, 2005b;Hess et al, 2006;Callait-Cardinal et al, 2007a). The primary transmission method of histomonas has, for long time, been thought to be its incorporation in the eggs of the small worm Heterakis gallinarum (Lund & Burtner, 1957;Ruff et al, 1970).…”

Section: Introductionmentioning

confidence: 99%

“…The primary transmission method of histomonas has, for long time, been thought to be its incorporation in the eggs of the small worm Heterakis gallinarum (Lund & Burtner, 1957;Ruff et al, 1970). However, recently, it was shown that direct lateral transmission within a flock may occur without the requirement of heterakis eggs (Hu & McDougald, 2003;Hess et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

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Quantification of parasite shedding and horizontal transmission parameters inHistomonas meleagridis-infected turkeys determined by real-time quantitative PCR

et al. 2015

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To gain more insight into the within flock transmission of Histomonas meleagridis, the shedding of parasites was quantified by a newly developed real-time quantitative (q)PCR and the basic reproduction number (R 0 ) and the mean number of secondary infections per infectious bird per day in a susceptible population (β) of H. meleagridis in the absence of heterakis were assessed. Forty turkeys were divided into two groups of 10 and 30 birds at 14 days of age. Birds of the first group were inoculated with 200,000 histomonads each, the second group served as a susceptible contact group. Cloacal swabs were taken at −1, 1, 4, 7, 9, 11, 14, 18 and 21 days post inoculation (p.i.) to assess the shedding of the parasite by the qPCR (detection limit 330 histomonads/ml droppings). The experiment ended at 28 days p.i. Mortality was 100% in the inoculated birds and started at day 12 p.i., while in the contacts, it was 83% and started at 16 days p.i. Shedding started 1 day after the inoculation in both groups. The mean shedding levels (and 95% CI) expressed as parasite equivalents per gram cloacal content on a log 10 scale in the inoculated, contact birds that died and contact birds alive were 2.0 (1.6-2.4), 1.6 (1.4-1.9) and 1.2 (0.5-2.0), respectively. Birds that died shed histomonas more often and were infectious for 13.4 days; in contrast, those that recovered were infectious for 5.7 days. R 0 was estimated to be 8.4 and β 0.70. Simulations made with the parameters obtained were in agreement with the experimental results, confirming their validity.

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Section: Discussionsupporting

confidence: 94%

Section: Discussioncontrasting

confidence: 40%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Quantification of parasite shedding and horizontal transmission parameters inHistomonas meleagridis-infected turkeys determined by real-time quantitative PCR

et al. 2015

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“…All birds were examined daily for adverse clinical signs and the body weight was measured weekly. At intervals of 3 to 4 days, cloacal swabs were taken and reisolation performed to monitor the excretion of live histomonads according to a recently described protocol (Hess et al, 2006a). Every week, blood samples were taken from birds of Groups CW2L, CW4L, VO and U.…”

Section: Methodsmentioning

confidence: 99%